Auto-setup qemu

riot/build.sh

@@ -22,6 +22,11 @@ function print_help() {
 
 require "$TAG" tag
 
+if ! docker run --rm -it arm64v8/ubuntu:19.10 /bin/bash -c 'echo "docker is configured correctly"'; then
+    echo "docker is not configured to run on qemu-emulated architectures, fixing will require sudo"
+    sudo docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
+fi
+
 set -xe
 
 sed "s/VERSION/$TAG/g" Dockerfile > "Dockerfile.$TAG"